Aquatic invasive species (AIS) are organisms that are not native and cause significant harm to an ecosystem when introduced. Harmful impacts can occur to municipal water supplies, recreation, agriculture, aquaculture, and other commercial activities.

Aquatic invasive species including amphibians, crustaceans, fish, plants, and mollusks are currently present in Wyoming, most notably the New Zealand mudsnail and Asian clam. While these species cause problems and need to be controlled, the most significant known threat to Wyoming is from zebra and quagga mussels based on their proximity and demonstrated impacts in neighboring states.